Project Summary. Disparities exist in all aspects of health care and have profound effects on health and the utilization of health services, including medications. Reducing disparities requires a detailed understanding of these causes. While disparities in many chronic conditions have been explored, little work has focused on rheumatoid arthritis (RA), the most common systemic rheumatic disease which is associated with increased mortality, disability and nearly 20 billion dollars in annual medical care costs in the US. RA drug treatment can substantially reduce pain and disability, and recommendations include disease-modifying anti-rheumatic drugs (DMARDs) for all patients. Several community-based studies document that only 30-60% of patients with RA receive DMARDs and that older age, black race and lower socioeconomic status all associate with under-use of DMARDs. Without a better understanding of these disparities, interventions are substantially hindered. The first aim of this research will examine geographic, ethnic, and socioeconomic disparities in RA treatment in nationally representative samples. We will use large representative national surveys with linked health care claims and/or geocoded Census information to gain a clearer picture of regional disparities in DMARD use, to determine whether both individual level and neighborhood level socioeconomic factors as well as and race and ethnicity play a role, and to identify how access to care affects prescribing. This information will allow us to assess how much of the variation in DMARD use can be explained by modifiable factors. The second aim will determine whether positive and negative changes in drug insurance status relate to changes in DMARD use for RA. Research supports the contention that gains and losses in insurance affect the use of all aspects of health services. We will analyze the new Medicare Part D drug coverage as well as information from younger patients enrolled in a longitudinal cohort of RA patients with over twenty years of data to assess how drug insurance affects access to DMARDs for RA. The third aim will identify ecologic and health system factors associated with disparities in the use of DMARDs for RA. Economically vulnerable neighborhoods, such as those with low rates of English as a primary language or low home ownership rates, and greater distance to rheumatologists and hospitals may all negatively impact disparities in RA care. We will work with linked utilization and geocoded data for enrollees with RA from several statewide health care insurance plans. In the final aim, we will survey patients to determine the attitudes, beliefs, and knowledge that contribute to disparities in DMARD use for RA. Neither the prior aims nor previous studies have incorporated information about patient's attitudes, beliefs, and knowledge into models of RA treatment disparities. We will purposefully sample patients with RA who do and do not receive DMARDs to determine whether they have been offered DMARDs in the past, their understanding of risks and benefits from these agents, and the usual sources of information they consult for making treatment decisions.